Sobue K, Okabe T, Kadowaki K, Itoh K, Tanaka T, Fujio Y
Proc Natl Acad Sci U S A. 1987 Apr;84(7):1916-20. doi: 10.1073/pnas.84.7.1916.
A Mr 35,000 calmodulin-binding protein, which also possesses the ability to interact with a number of cytoskeletal elements, was purified from bovine synaptosomal membranes, using hydroxylapatite and phosphocellulose column chromatography. We call this protein "cytosynalin," which is derived from a combination of the words "cytoskeleton" and "synapsis." Indirect immunofluorescent staining of cytosynalin revealed that it is distributed throughout neural cells including in dendrites, varicosities, and growth cones. In 3T3 cells, cytosynalin is located on the inner surface of the plasma membrane. The staining pattern of cytosynalin observed with anti-cytosynalin antibodies was similar to that observed with antibodies against calspectin (nonerythroid spectrin or fodrin). Cytosynalin binds to calspectin and to tubulin and actin filaments, as determined by binding assays, turbidity measurements, low-shear viscometry, and electron microscopy. Furthermore, after heating at 90 degrees C for 5 min, cytosynalin retains its binding activity toward calmodulin and cytoskeletal elements. These results lead to the conclusion that cytosynalin is colocalized with calspectin at the inner surface of the plasma membrane, probably in association with other cytoskeletal elements.
一种分子量为35000的钙调蛋白结合蛋白，它还具有与多种细胞骨架成分相互作用的能力，利用羟基磷灰石和磷酸纤维素柱色谱法从牛突触体膜中纯化得到。我们将这种蛋白称为“细胞突触联蛋白”，它是由“细胞骨架”和“突触”这两个词组合而来。对细胞突触联蛋白进行间接免疫荧光染色显示，它分布于整个神经细胞，包括树突、膨体和生长锥。在3T3细胞中，细胞突触联蛋白位于质膜内表面。用抗细胞突触联蛋白抗体观察到的细胞突触联蛋白染色模式与用抗钙视蛋白（非红细胞血影蛋白或 fodrin）抗体观察到的相似。通过结合试验、浊度测量、低剪切粘度测定和电子显微镜确定，细胞突触联蛋白与钙视蛋白、微管蛋白和肌动蛋白丝结合。此外，在90℃加热5分钟后，细胞突触联蛋白仍保留其对钙调蛋白和细胞骨架成分的结合活性。这些结果得出结论，细胞突触联蛋白与钙视蛋白共定位于质膜内表面，可能与其他细胞骨架成分相关联。
